.\" RCSid "$Id: compamb.1,v 1.3 2007/09/04 17:36:40 greg Exp $"
.TH COMPAMB 1 1/23/98 RADIANCE
.SH NAME
compamb - compute good ambient value for a rad input file
.SH SYNOPSIS
.B compamb
[
.B \-c
][
.B \-e
]
.B rad_input_file
.SH DESCRIPTION
.I Compamb
computes a good ambient value for the specified
.I rad(1)
variable file and appends it to the file as a "render= \-av" option.
If the
.I \-c
option is specified, then
.I compamb
includes color information in the computed ambient value, rather than
estimating a grey value to avoid rendering color shifts.
If the
.I \-e
option is specified, then
.I compamb
also computes a good exposure value for this scene, and appends it to
the
.I rad
file as well.
.PP
.I Compamb
is a shell script that makes calls to other RADIANCE programs and utilities
to do the actual work.
A substantial amount of time may be required to complete this script, since
.I compamb
calls
.I rpict(1)
to render low resolution frames for each view in the
.I rad
file, setting "QUALITY=High" to compute interreflections.
The resulting ambient file is thrown away, since it would disagree
with the new \-av setting used for the final renderings.
This method is preferable to setting the
.I \-aw
option of
.I rpict,
which frequently results in splotchy artifacts.
.SH AUTHOR
Greg Ward Larson
.SH "SEE ALSO"
lookamb(1), rad(1), rpict(1)
